How can i get a better result Baking in blender render?
At first glance I would think that noise is due to a low sample setting.

You might try to increase the gathering samples.
Go  into the "Scene Settings" in the "Properties Editor", under "Gather", if you set it to use raytracing, you can change the sample settings.

But yeah, just a guess into the wild, maybe I am wrong? Hard to say without having the scene open...